U.S. patent number 10,233,466 [Application Number 14/983,265] was granted by the patent office on 2019-03-19 for economic ethanol fermentation sugar stream, processes and systems of producing same.
This patent grant is currently assigned to Poet Research, Inc.. The grantee listed for this patent is POET Research, Inc.. Invention is credited to Steven Redford.
United States Patent |
10,233,466 |
Redford |
March 19, 2019 |
**Please see images for:
( Certificate of Correction ) ** |
Economic ethanol fermentation sugar stream, processes and systems
of producing same
Abstract
Methods and system for producing a slip stream of sugar, for
example for use in the production of one or more chemicals, in
ethanol fermentation facilities. In some embodiments, the methods
and systems have little to no impact on the level of production of
ethanol, despite also producing a slip stream of sugar. The methods
and systems can be implemented in dry mill ethanol, wet mill
ethanol, and lignocellulosic ethanol fermentation facilities and
processes.
Inventors: |
Redford; Steven (Brandon,
SD) |
Applicant: |
Name |
City |
State |
Country |
Type |
POET Research, Inc. |
Sioux Falls |
SD |
US |
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Assignee: |
Poet Research, Inc. (Sioux
Falls, SD)
|
Family
ID: |
56163500 |
Appl.
No.: |
14/983,265 |
Filed: |
December 29, 2015 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160186215 A1 |
Jun 30, 2016 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62098434 |
Dec 31, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C12M
21/12 (20130101); C12P 19/02 (20130101); C12P
7/06 (20130101); Y02E 50/16 (20130101); Y02E
50/10 (20130101); Y02E 50/17 (20130101) |
Current International
Class: |
C12P
7/06 (20060101); C12M 1/00 (20060101); C12P
19/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Kwiatkowski et al. "Modeling the process and costs of fuel ethanol
production by the corn dry-grind process" Industrial Crops and
Products 23 (2006) 288-296 (Year: 2006). cited by examiner .
International Search Report and Written Opinion from International
Application No. PCT/US2015/067944, dated Apr. 15, 2016 (12 pages).
cited by applicant.
|
Primary Examiner: Underdahl; Thane
Attorney, Agent or Firm: Kagan Binder, PLLC
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent
Application No. 62/098,434, entitled, "Economic Ethanol
Fermentation Sugar Stream, Processes and Systems of Producing
Same," and having a filing date of Dec. 31, 2014. This provisional
application is herein incorporated by reference in its entirety.
Claims
What is claimed is:
1. A process for producing streams of sugar in a dry mill ethanol
fermentation facility comprising the following steps: (i) dry
grinding a grain to produce a around feedstock stream; (ii)
dividing the ground feedstock stream into a first ground feedstock
and a second ground feedstock, (iii) providing the first around
feedstock to a first process flow comprising the following steps:
(a) saccharifying the first ground feedstock with an enzyme to
produce the first sugar stream comprising simple sugars, solids,
and enzymes from the first around feedstock; and (b) providing the
first sugar stream to a non-ethanol chemical process; (iv)
providing the second around feedstock to a second process flow
comprising the following steps: (a) saccharifying the second ground
feedstock with an enzyme to produce the second sugar stream
comprising simple sugars, solids, and enzymes from the second
around feedstock; (b) fermenting the second sugar stream with a
yeast to produce a beer; (c) separating an ethanol stream and a
solids stream from the beer; and (d) drying the solids stream to
produce dried distillers grain.
2. The process according to claim 1, wherein the grain is a whole
cereal.
3. The process according to claim 2, wherein the whole cereal is
corn.
4. The process according to claim 3, further comprising
fractionating the corn.
5. The process of claim 1, further comprising separating any solids
from the first process flow and introducing the separated solids
into the second process flow.
6. The process according to claim 5, wherein the introducing the
solids into the second process flow results in a total amount of
solids in the second process flow that does not negatively impact
the ethanol titer.
7. The process of claim 5, further comprising introducing the
separated solids into the fermenting step of the second process
flow.
8. The process of claim 5, further comprising introducing the
separated solids into the drying step of the second process
flow.
9. The process according to claim 1, wherein the second sugar
stream produces up to the maximum ethanol titer compared to the
same ethanol facility producing ethanol without the two process
flows.
10. The process according to claim 1, wherein the amount of ground
feedstock stream is chosen to produce an ethanol titer that is in
excess of the maximum titer of the ethanol fermentation facility,
if both the first sugar and second sugar streams were
fermented.
11. The process according to claim 1, wherein the amount of ground
feedstock stream is chosen to produce an ethanol titer that is
greater than the yeast can tolerate, if both the first sugar and
second sugar streams were fermented.
12. The process of claim 1 further comprising removing enzymes from
the first sugar stream and recycling the removed enzymes into the
second process flow.
13. The process of claim 1, wherein dividing the ground feedstock
comprises removing from about 2% to 5% by volume of the ground
feedstock, wherein the removed feedstock is the first ground
feedstock stream and the remaining feedstock is the second ground
feedstock stream.
14. The process of claim 1, wherein the ethanol stream comprises no
less than 10% of the ethanol titer compared to the same ethanol
fermentation facility producing ethanol without the two process
flows.
15. A process for producing streams of sugar in a dry mill ethanol
fermentation facility comprising the following steps: (i) dry
grinding a grain to produce a around feedstock stream; (ii)
saccharifying the ground feedstock stream with an enzyme to produce
a sugar stream comprising simple sugars, solids, and enzymes from
the ground feedstock stream; (iii) dividing the sugar stream into a
first sugar stream and a second sugar stream (iv) providing the
first sugar stream to a first process flow comprising providing the
first sugar stream to a non-ethanol chemical process; and (v)
providing the second sugar stream to a second process flow
comprising the following steps: (a) fermenting the second sugar
stream with a yeast to produce a beer; (b) separating an ethanol
stream and a solids stream from the beer; and (c) drying the solids
stream to produce dried distillers grain.
16. The process of claim 15, wherein the feedstock grain is a whole
cereal.
17. The process of claim 16, wherein the whole cereal is corn.
18. The process of claim 17, further comprising fractionating the
corn.
19. The process of claim 15, further comprising separating solids
from the first sugar stream and introducing the solids into the
second process flow after fermenting the second sugar stream.
20. The process of claim 15, further comprising removing enzymes
from the first sugar stream and recycling the removed enzymes into
the second process flow.
Description
FIELD
The specification relates to methods and systems for producing
sugar in ethanol fermentation facilities. The specification also
relates to methods and systems for simultaneously producing ethanol
and a slip stream of sugar, for example for the production of
non-ethanol chemicals in ethanol fermentation facilities with
little to no impact on the ethanol facility's alcohol yield.
BACKGROUND
First generation ethanol fermentation facilities produce ethanol
from starch-based feedstock such as corn. In a typical conventional
corn-to-ethanol fermentation process, starch present in corn is
broken down into simple sugars, which can be fermented by an
ethanologen such as yeast into ethanol.
Traditional ethanol production processes typically involve five
basic steps: milling, cooking, saccharification, fermentation,
distillation and recovery. In some such processes, the milling step
is a dry milling step in which corn is ground into flour. Cooking
may involve mixing the flour with water to form a slurry, heating
the slurry to above the gelatinization temperature of the corn, and
treating the slurry with a liquefying enzyme to hydrolyze starch
contained therein to dextrins. In the saccharification step,
enzymes are added to the mash to convert the corn starch into
simple sugars. The fermentation of the sugars by an ethanologen
such as yeast produces a beer, which is separated into ethanol and
whole stillage by distillation. The whole stillage may be subject
to further processing wherein it is separated into wet cake and
thin stillage. The thin stillage passes through evaporators to
produce a syrup, which may be recombined and dried with the wet
cake to produce distillers grains with solubles (DDGS), an animal
feed. Not all dry mill ethanol production processes involve all the
identified steps. For example, in some dry mill ethanol production
processes, saccharification and fermentation are not independent
steps but occur simultaneously. As another example, some dry mill
ethanol production processes do not involve liquefaction. As yet
another example, POET.RTM.'s BPX.RTM. hydrolysis process does not
use a jet cooker (i.e. a cooking step).
In order to produce a pure sugar stream while also making other
components of corn available to sell, some conventional processes
use a wet mill rather than dry mill approach. In wet milling, corn
is soaked in water to soften the grain and facilitate separating
the various components of the corn kernel. After "steeping",
various components such as starch, fiber and germ are separated
from one another for separate processing into a variety of
products. Fractionation equipment, however, is expensive and
increases the cost of producing the sugar stream.
SUMMARY
The present disclosure relates in part to methods and systems for
simultaneously producing a slip stream of sugar stream, for example
for the production of non-ethanol chemicals, as well as a sugar
stream for the production of ethanol in ethanol fermentation
facilities while essentially maintaining the same ethanol titer as
could be produced by the same facility if it did not produce the
biochemical sugar stream.
In some such embodiments, the methods involve producing a slip
stream of sugar in an ethanol fermentation facility configured to
produce a desired ethanol titer by preparing a fermentable stream
from an amount of feedstock, removing a first portion of the
fermentable stream prior to fermentation by an ethanologen, and
producing ethanol from the second, remaining portion of the
fermentable stream consistent with the desired ethanol titer. In
some embodiments, the first portion is removed after
saccharification of the fermentable stream. In some embodiments,
the first portion is removed prior to saccharification of the
fermentable stream.
In some embodiments, the methods are implemented in a first
generation (starch-based) ethanol fermentation facility and the
fermentable stream is a slurry or a mash. In some further
embodiments, wherein the fermentable stream is a mash, the mash is
processed to remove solids and produce a sugar stream. The first
generation process may be any process for converting starch-based
materials such as corn into ethanol, for example including both
processes which include and do not include a cooking step. In yet
further embodiments, the removed solids are returned to the second
portion of the fermentable stream (i.e. mash). In further
embodiments, the sugar stream is also processed, for example the
sugar stream is filtered using a membrane, to remove enzymes and
the removed enzymes are recycled into the second portion of the
fermentable stream (i.e. mash).
In other further embodiments, wherein the fermentable stream is a
slurry, both the first portion of the slurry is processed into a
first mash and the second portion of the slurry is processed as per
usual into a second mash. In certain further embodiments, the first
mash is further processed to remove solids and produce a sugar
stream. In yet further embodiments, the removed solids are combined
with the second mash. In further embodiments, the sugar stream is
also processed, for example the sugar stream is filtered using a
membrane, to remove enzymes and the removed enzymes are recycled
into the second portion of the fermentable stream (i.e. mash).
In some embodiments, the process is implemented in a
lignocellulosic (also referred to as cellulosic) ethanol
fermentation facility. In further embodiments, the fermentable
stream is removed before saccharification. In other further
embodiments, the fermentable stream is a saccharified liquor and
therefore the fermentable stream is removed after saccharification.
In some embodiments, the fermentable stream, for example the
saccharified liquor, is further processed to produce a sugar
stream.
In certain embodiments the desired ethanol titer is approximately
the ethanol-producing facility's maximum titer. For example, in
certain embodiments, an amount of feedstock is used which generates
a fermentable stream (e.g. mash) from which both a first portion
for production of non-ethanol chemicals and a second portion for
production of ethanol are derived, wherein the second portion is
capable of producing the maximum titer of ethanol independently of
the first portion. As another example, an amount of feedstock is
used which produces a fermentable stream that if fermented without
separation into a first portion for production of non-ethanol
chemicals and second portion for production of ethanol would result
in an ethanol titer in excess of what the fermentation facility's
ethanologen can tolerate. In some embodiments, the amount of
feedstock ranges from an amount that would produce an ethanol titer
that is too high for the ethanologen to tolerate if both the first
fermentable stream (e.g. mash) and second fermentable stream (e.g.
mash) could be fermented in the same tank volume to an amount of
feedstock consistent with the ethanol fermentation facility's
capability.
In some embodiments, the systems comprise an ethanol fermentation
facility configured to produce a desired titer of ethanol, and
componentry configured to remove a slip stream from a fermentable
stream produced in the facility with essentially little or no
impact to the desired ethanol titer production. In some
embodiments, the componentry is configured to remove the slip
stream after saccharification. In some embodiments the componentry
is configured to remove the slip stream before saccharification. In
some embodiments the systems further comprise componentry to
separate and/or return solids derived from the slip stream back to
the ethanol facility, for example back to a mash or a saccharified
liquor produced in the facility. In further embodiments, the
systems further comprise componentry to separate residual enzymes
from the sugar stream after removal of solids and return the
enzymes back to the ethanol facility. In some embodiments, the
facility is a starch-based ethanol facility. In some embodiments,
the facility is a dry mill starch-based ethanol facility. In some
embodiments, the facility is a dry mill corn-to-ethanol facility.
In some embodiments, the facility is a lignocellulosic ethanol
facility.
The identified embodiments are exemplary only and are therefore
non-limiting. The details of one or more non-limiting embodiments
according to the disclosure are set forth in the descriptions
below. Other embodiments according to the disclosure should be
apparent to those of ordinary skill in the art after consideration
of the present disclosure. For example, although implementations of
the processes and systems are primarily described herein with
reference to dry mill ethanol production processes and systems,
they may be adapted to wet mill ethanol processes and systems, as
well as lignocellulosic ethanol processes and systems as a person
of skill in the art would readily understand from reading this
specification. Similarly, although implementations of the processes
and systems primarily refer to corn-to-ethanol fermentation
processes and systems, they may be adapted to other
biomass-to-ethanol fermentation processes and systems, again as a
person of skill could understand from reading this
specification.
DETAILED DESCRIPTION
Unless defined otherwise, all technical and scientific terms used
herein have the same meaning as is commonly understood by one of
ordinary skill in the art to which this disclosure belongs. In the
event that there is a plurality of definitions for a term herein,
those in this section prevail unless stated otherwise.
Where ever the phrases "for example," "such as," "including" and
the like are used herein, the phrase "and without limitation" is
understood to follow unless explicitly stated otherwise.
The terms "comprising" and "including" and "involving" (and
similarly "comprises" and "includes" and "involves") are used
interchangeably and mean the same thing. Specifically, each of the
terms is defined consistent with the common United States patent
law definition of "comprising" and is therefore interpreted to be
an open term meaning "at least the following" and also interpreted
not to exclude additional features, limitations, aspects, etc.
The term "about" is meant to account for variations due to
experimental error or to permit deviations from the measurements
that don't negatively impact the intended purpose. All measurements
or numbers are implicitly understood to be modified by the word
about, even if the measurement or number is not explicitly modified
by the word about.
The term "substantially" is meant to permit deviations from the
descriptive term that don't negatively impact the intended purpose.
All descriptive terms are implicitly understood to be modified by
the word substantially, even if the descriptive term is not
explicitly modified by the word substantially.
Where ever the terms "a" or "an" are used, "one or more" is
understood unless explicitly stated otherwise or such
interpretation is nonsensical in context.
The phrases: "essentially maintaining the same ethanol titer";
"with little or no impact to the ethanol facility's alcohol yield";
"consistent with the desired ethanol titer" and the like imply that
for a given ethanol facility implementing a slip stream sugar
process according to this disclosure any resulting reduction of
ethanol production is commercially acceptable. For example, the
difference in ethanol titer between a facility producing ethanol
and a slip stream of sugar according to this disclosure and the
same ethanol facility producing ethanol without the slip stream of
sugar may be about 10%, or about 5%, or about 2%, or about 0%.
"Mash" refers to a composition comprising sugar produced in a
starch-based facility. "Saccharified liquor" refers to a
composition comprising sugar produced in a lignocellulosic ethanol
facility. "Slurry" refers to a starch composition produced in a
starch-based facility.
The phrase "sugar stream" refers to a composition that comprises
sugar; a sugar stream is not necessarily pure sugar, but may be for
example a mash or a purified mash (such as a mash that has been
processed to remove at least a portion of solids). "Sugar stream"
also refers to a stream which is diverted from an ethanol
fermentation facility to provide a second source of sugar distinct
from the main source of sugar which will be used to produce
ethanol. Sugar in the sugar stream may be used, for example, to
produce one or more chemicals.
The phrases: "removing solids from the first portion of the
fermentable stream" and "removing enzymes from the sugar stream" as
well as other similar phrases suggesting a purification or
separation process do not require complete
removal/separation/purification.
The present disclosure relates to methods and systems for producing
a sugar stream, for example for use in production of non-ethanol
chemicals, while also producing ethanol in a feedstock-to-ethanol
fermentation process. In some embodiments, the present disclosure
provides methods and systems for producing a sugar stream, for
example for use in production of non-ethanol chemicals, while
simultaneously maintaining ethanol production at a
commercially-acceptable level, for example at essentially maximum
titer levels according to the implementing ethanol fermentation
facility's capability.
Ethanol fermentation processes generally involve producing a
fermentable stream from a feedstock (for example a grain-based
starch feedstock including whole cereal such as corn, wheat,
sorghum, bulgur, barley) and thereafter producing ethanol from the
fermentable stream. For example, in a starch-based ethanol
fermentation process, the fermentable stream may be a mash, and
producing ethanol involves fermenting sugar in the mash into
ethanol. As another starch-based example, the fermentable stream
may be a slurry, which is saccharified to produce a mash. The sugar
in the mash is thereafter fermented into ethanol. As yet another
example, in a lignocellulosic ethanol fermentation process, the
fermentable stream may be a saccharified liquor, and producing
ethanol involves fermenting sugar in the saccharified liquor into
ethanol.
In some embodiments, methods described herein generally involve
producing a fermentable stream in excess of what the implementing
facility typically handles or is capable of handling, producing a
slip stream of sugar from the excess fermentable stream, and
producing ethanol from the remaining fermentable stream. In
general, the methods involve preparing a fermentable stream from an
amount of feedstock, removing a first portion of the fermentable
stream prior to fermentation by an ethanologen, and producing
ethanol from a second portion of the fermentable stream consistent
with the desired ethanol titer.
In some embodiments, the first portion (of the fermentable stream)
is removed after saccharification of the fermentable feed stream.
In some such embodiments, this sugar slip stream (removed first
portion) may be further purified by removing solids according to
any appropriate method, such as any method known to those of
ordinary skill in the art. In further embodiments, the removed
solids are returned to the ethanol fermentation facility and may be
recombined with the second portion of the fermentation stream or a
stream derived from the second portion. In yet further embodiments,
the resultant sugar stream is also subjected to a purification
process targeted to remove residual enzymes. In some such
embodiments, the removed residual enzymes are returned for re-use
in the ethanol fermentation facility, such as recombined with the
second portion of the fermentation stream or other stream derived
from the second portion.
In some embodiments, the first portion of the fermentable stream is
removed before saccharification of the fermentable stream. In some
such embodiments, the first portion is further processed to produce
sugar (such as by being subjected to a saccharification process),
and the resultant sugar slip stream may be further purified, for
example to remove solids. In further embodiments, the removed
solids may be recombined with the second portion of the
fermentation stream or a stream derived from the second
portion.
In some embodiments, the desired ethanol titer is a
commercially-acceptable titer. In some embodiments, the desired
ethanol titer is the ethanol producing-facility's maximum ethanol
titer. Accordingly, in some embodiments, the amount of feedstock is
chosen to produce the desired ethanol titer that is in excess of
the implementing ethanol-producing facility's capability if both
the first portion of the fermentable stream and second portion of
the fermentable stream could both be fermented in the same tank. In
some embodiments, the amount of feedstock is chosen such that the
second portion of the fermentable stream produces the desired
ethanol titer. In some such embodiments, the resultant ethanol
titer is a commercially-acceptable titer; in other such
embodiments, the resultant ethanol titer is the ethanol facility's
maximum operational ethanol titer. In some embodiments, the amount
of feedstock is chosen to produce an ethanol titer that is greater
than the ethanologen can tolerate, if both the first portion and
second portion of the fermentable stream could be fermented in the
same tank. In some embodiments, the chosen amount of feedstock may
range from an amount that produces an ethanol titer greater than
the ethanologen can tolerate to an amount that is greater than the
implementing facility's capability. The chosen amount of feedstock
may be limited by a given facility's operational parameters; a
person of ordinary skill could determine the limit based on this
specification and knowledge of the operations of the implementing
facility.
In some embodiments, the methods may be implemented in first
generation (e.g. starch-based) ethanol fermentation processes, such
as a dry mill ethanol fermentation process. In other words, the
"implementing facility" mentioned throughout may be a first
generation ethanol fermentation facility, including facilities
which use cooking steps and which do not use cooking steps in their
hydrolysis process. A dry mill corn ethanol process typically
involves: milling corn; slurring the corn with water; steam
exploding the solids; liquefying/saccharifying the stream with
enzymes; fermenting the mash; distilling the alcohol from the beer;
separating the solids form the whole stillage to create wet cake;
evaporating some of the water from the thin stillage to create
syrup; removal of oil from the syrup; and, drying the wet cake and
the syrup. However, the processes described herein are not limited
in application to this typical process but may be applied to all
dry mill processes including, for example, dry mill processes which
do not use steam explosion or other cooking steps. In general,
ethanol plants are designed to operate as efficiently as possible,
i.e. to produce as high an ethanol titer as is possible. Dry mill
plants typically produce titers ranging from about 12% to about
20%. Obstacles limiting the titer include the ethanologen used to
ferment the sugars, and non-fermentable components ("inerts")
produced in the overall process. For example, the ethanologen may
not be able to tolerate higher titer, and the presence of a certain
level of inerts may impact the yield of alcohol.
In order to produce a stream of sugar while still maintaining the
ethanol titer, methods according to the present disclosure mill an
increased amount of feedstock relative to the typical amount of
feedstock used as input in a given dry mill ethanol fermentation
facility process, and thereby increase the amount of sugar produced
in the mash relative to the amount of sugar produced if the plant
were only producing a sugar stream for ethanol. For example, in
some dry mill embodiments, the amount of feedstock is chosen to
produce an ethanol titer that is in excess of the maximum titer of
the given ethanol fermentation facility. For example the amount of
feedstock is chosen such that only a portion of the fermentation
stream produced from the feedstock is required to produce the
maximum ethanol titer for the given ethanol fermentation facility.
In other dry mill embodiments, the amount of feedstock is chosen to
produce an ethanol titer and/or inerts that is greater than the
ethanologen can tolerate. In some dry mill embodiments, the amount
of feedstock ranges from an amount that would produce an ethanol
titer that is too high for the ethanologen to an amount of
feedstock consistent with the ethanol fermentation facility's
capability. In some dry mill embodiments, the amount of feedstock
may be augmented above the limits described above by removing one
or more components from the feedstock, such as removing fiber from
the corn, thereby decreasing the level of inerts entering the
fermenter per given amount of feedstock and allowing for greater
grind and sugar removal. In some embodiments, the removed feedstock
components are introduced back into the system at an appropriate
location, such as providing removed corn fiber to the DDGS.
The additional grind results in a larger portion of fermentable
stream, which in some embodiments would produce sugar that exceeds
the fermentation facility's processing capability (such as by
creating ethanol titers that are too high for the ethanologen to
tolerate, or such as by producing an amount of inerts that impacts
ethanol yield beyond what is commercially acceptable). Accordingly,
a portion of the fermentable stream is removed prior to
fermentation.
In some embodiments, therefore, a first portion of the fermentable
stream is removed, for example for the purpose of providing a slip
stream of sugar for non-ethanol chemical(s) rather than ethanol
production, and the second, remaining portion may be fermented into
ethanol. In some embodiments, the first portion of mash is removed
after saccharification. In some dry mill embodiments, the first
portion of the fermentable stream is removed after
saccharification. Such methods may involve producing a slip stream
of sugar in an ethanol fermentation facility configured to produce
a desired ethanol titer by preparing a mash from an amount of
feedstock, removing a first portion of the mash prior to
fermentation by an ethanologen, which corresponds to the slip
stream of sugar, and producing ethanol from the second, remaining
portion of the mash consistent with the desired ethanol titer.
In other dry mill embodiments, the first portion of the fermentable
stream is removed before saccharification. Such methods may involve
producing a slip stream of sugar in an ethanol fermentation
facility configured to produce a desired ethanol titer by a
preparing a slurry from an amount of feedstock, removing a first
portion of the slurry, processing the first portion of the slurry
to produce a sugar stream (for example directing the slurry to a
liquefaction and/or saccharification process), and producing
ethanol from the second, remaining portion of the slurry consistent
with the desired ethanol.
The removed mash (whether removed directly as the fermentable
stream or generated from the removed fermentable stream) may be
processed according to any method to generate a purified sugar slip
stream. For example, the removed mash may be processed to separate
out solids present in the mash, resulting in a sugar slip stream.
The sugar slip stream may serve as a source of sugar for production
of one or more chemicals. In some embodiments, the separated solids
may be combined with the mash which is to be fermented to produce
ethanol for processing and recovery in the usual course of the
facility's operation. In such embodiments, the level of
non-fermentable material ("inerts") that the fermentation process
can handle to maintain desired efficiencies of the ethanol process
will control the amount of sugar that can be produced for the
chemical sugar slip stream and in turn the amount of additional
input feedstock that may be used over and above what is used during
usual operation of the facility (i.e. when the facility is
operating to only produce a sugar stream for ethanol
production).
In some embodiments, in addition to recycling solids from the first
portion of the fermentable stream, enzymes in the sugar stream are
also recycled into the ethanol fermentation process. For example,
after solids are removed, the resultant sugar stream may be
subjected to a filtration process to remove enzymes. In some
embodiments, recycling enzymes into the fermentation process from
the removed solids and/or from the sugar stream provides an
economic benefit in that fewer enzymes need to be used in the
ethanol fermentation process. To illustrate the point, if: 100% of
the enzymes in the slip stream could be recycled; and if the
combined volume of the first portion and second portion represents
100% of the fermentable volume, with the first portion being 20% of
the total fermentable volume and the second portion representing
80% of the total fermentable volume; then only a quantity of
enzymes needed for 60% of the total fermentable volume needs to be
added to the second portion because the remaining amount of
required enzyme may be recycled into the second portion from the
first portion.
In any of the above-described embodiments, the portion of
fermentable stream removed may be chosen such that the remaining
portion of fermentable stream is typical of the amount of
fermentable stream processed by the given fermentation facility to
achieve its desired (for example maximum) ethanol titer. That is,
an amount of sugar may be removed (directly by removing a portion
of the mash or indirectly by removing a portion of slurry) to
maintain the same amount of sugar for the given facility's typical
ethanol production and consequently ethanol titer.
In some dry mill embodiments, up to about 25% by volume of the
fermentable stream (e.g. mash) may be removed prior to
fermentation. In some dry mill embodiments, up to about 15% by
volume of the fermentable stream (e.g. mash) may be removed prior
to fermentation. In some dry mill embodiments, up to about 10% by
volume of the fermentable stream (e.g. mash) may be removed prior
to fermentation. In some dry mill embodiments, up to about 5% by
volume of the fermentable stream (e.g. mash) may be removed prior
to fermentation. In some dry mill embodiments, from about 10% to
about 15% by volume of the fermentable stream (e.g. mash) may be
removed prior to fermentation. In some dry mill embodiments, from
about 8% to about 10% by volume of the fermentable stream (e.g.
mash) may be removed prior to fermentation. In some dry mill
embodiments, from about 2% to about 5% by volume of the fermentable
stream (e.g. mash) may be removed prior to fermentation.
In general, the upper limit of additional fermentable stream (e.g.
mash) that may be produced and accordingly the upper limit of
fermentable stream (e.g. mash) that may be removed relates to a
given facility's processing parameters. For example, facilities
that operate at lower titers may generally be able to grind more
and therefore remove more fermentable stream (e.g. mash) relative
facilities that operate at higher titer. The amount of additional
fermentable stream (e.g. mash) that may be provided to the
fermenter also depends on the chosen ethanologen and the level of
inerts and/or titer it can tolerate. The amount of fermentable
stream (e.g. mash) that may be removed also depends on ethanol loss
that is acceptable to a given facility. For example, if a facility
can accept a 10% loss in ethanol, it can remove larger amounts of
sugar relative to a facility that desires to maintain its ethanol
yield. As another example, if the facility can accept little to no
loss in ethanol and the facility is operating at high titer, it may
only be able to remove a small amount of fermentable stream (e.g.
mash) by over grinding.
In some dry mill embodiments, the amount of feedstock may exceed
the above guidelines if one or more components of the feedstock is
removed in advance of fermentation, for example in advance of
introducing the feedstock into the process or for example in
advance of liquefaction, thereby decreasing the inerts that come
into the fermenter permitting a greater grind and mash/sugar
removal. As an example, the feedstock may be corn, and the removed
component may be fiber. In some embodiments, the removed component
or components, such as fiber, is/are sent directly to the Dried
Distillers Grain ("DDG"). For example, in some such embodiments
wherein components of the feedstock are removed upfront, up to
about 37%, or up to about 40% by volume of the fermentable stream
may be removed prior to fermentation.
The present disclosure also provides systems for producing a slip
stream of sugar. The systems include an ethanol fermentation
facility and componentry configured to remove a slip stream from a
fermentation stream produced in the facility with essentially no
impact to the desired ethanol titer production. In some
embodiments, the ethanol facility is configured to produce ethanol
from a whole cereal, such as corn. In some embodiments, the ethanol
facility is configured to produce ethanol from lignocellulosic
biomass. In some embodiments, the componentry is configured to
remove the slip stream after saccharification of the fermentable
stream. In some embodiments the componentry is configured to remove
the slip stream before saccharification of the fermentable stream.
In some embodiments, the system provides processing equipment for
purifying the slip stream and returning components removed from the
slip stream (such as solids removed from mash) back into the stream
for production of ethanol (such as back into the mash in a
starch-based facility or back into the saccharified liquor in a
lignocelllulosic facility). In some embodiments, wherein the
fermentable stream is removed prior to saccharification, the system
also includes componentry for further processing of the stream to
produce sugar.
A number of embodiments have been described but a person of skill
understands that still other embodiments are encompassed by this
disclosure. It will be appreciated by those skilled in the art that
changes could be made to the embodiments described above without
departing from the broad inventive concepts thereof. For example,
although the process is described primarily with respect to dry
mill processes, it could also be adapted to wet mill processes. It
is understood, therefore, that this disclosure and the inventive
concepts are not limited to the particular embodiments disclosed,
but are intended to cover modifications within the spirit and scope
of the inventive concepts including as defined in the appended
claims. Accordingly, the foregoing description of various
embodiments does not necessarily imply exclusion. For example,
"some" embodiments or "other" embodiments may include all or part
of "some", "other," "further," and "certain" embodiments within the
scope of this invention. Methods and devices within the scope of
the disclosure can also be defined in accordance with the below
embodiments.
Non-Inclusive Additional Embodiments
1. A process for producing a slip stream of sugar implemented in an
ethanol-producing fermentation facility configured to produce a
desired ethanol titer, comprising: a. preparing a fermentable
stream from an amount of feedstock; b. removing a first portion of
the fermentable stream prior to fermentation by an ethanologen;
and, c. producing ethanol from a second portion of the fermentable
stream consistent with the desired ethanol titer. 2. A process
according to embodiment 1, wherein the desired ethanol titer is
approximately the ethanol-producing facility's maximum titer. 3. A
process according to embodiment 1 or embodiment 2, further
comprising: separating solids from the first portion of the
fermentable stream and providing the solids at least to the second
portion of the fermentable stream to produce a total amount of
solids in the second portion. 4. A process according to embodiment
1 or embodiment 2, wherein the amount of feedstock is chosen to
produce an ethanol titer that is in excess of the maximum titer of
the ethanol-producing facility, if both the first portion and
second portion of the fermentable stream were fermented. 5. A
process according to embodiment 1 or embodiment 2, wherein the
amount of feedstock is chosen to produce an ethanol titer that is
greater than the ethanologen can tolerate, if both the first
portion and second portion of the fermentable stream were
fermented. 6. A process according to embodiment 3, wherein the
total amount of solids in the second portion does not negatively
impact the desired ethanol titer. 7. A process according to
embodiment 3, wherein the process maintains the desired ethanol
titer. 8. A process according to any of embodiments 1-7, wherein
the fermentable stream is chosen from a slurry, a mash, and a
saccharified liquor. 9. A process according to embodiment 8,
wherein the process is implemented in a starch-based ethanol
fermentation facility and the fermentable stream is a slurry or a
mash. 10. A process according to embodiment 9, wherein the first
portion is removed after saccharification and the fermentable
stream is a mash. 11. A process according to embodiment 9, wherein
the first portion is removed before saccharification and the
fermentable stream is a slurry. 12. A process according to
embodiment 10 or embodiment 11, wherein the feedstock is a whole
cereal. 13. A process according to embodiment 12, wherein the
feedstock is corn. 14. A process according to any of embodiments 6,
7, and 9-12, wherein the process is implemented in a starch-based
ethanol fermentation facility and comprises: a. milling the
feedstock; b. cooking the milled feedstock, wherein cooking
comprises mixing the milled feedstock to form a slurry and
hydrolyzing the slurried feedstock to produce dextrins; and, if
necessary, c. saccharifying the dextrins to produce glucose. 15. A
process according to embodiment 14, wherein the feedstock has a
gelatinazation temperature and hydrolysis is performed above the
gelatinization temperature of the feedstock. 16. A process
according to embodiment 14, further comprising fractionating the
feedstock. 17. A process according to any of embodiments 1-10 and
12-16, further comprising separating sugar from the first portion
of the fermentable stream. 18. A process according to embodiment
17, further comprising using the sugar to produce one or more
chemicals. 19. A process according to any of embodiments 1-9 and
11-16, further comprising directing the first portion to a
liquefaction process, saccharification process or both to produce a
mash; and processing the mash to produce a sugar stream. 20. A
process according to embodiment 19, wherein the sugar stream
derived from the first portion is used to produce one or more
chemicals. 21. A system for producing a slip stream of sugar,
comprising: a. an ethanol fermentation facility configured to
produce a desired titer of ethanol from a whole cereal; b.
componentry configured to remove a slip stream from a fermentable
stream produced in the facility with essentially no impact to the
desired ethanol titer production. 22. A system according to
embodiment 21, wherein the desired ethanol titer is approximately
the ethanol fermentation facility's maximum titer. 23. A system
according to embodiments 21 or 22, wherein the componentry is
configured to remove the slip stream after saccharification. 24. A
system according to embodiments 21 or 22, wherein the componentry
is configured to remove the slip stream before saccharification.
25. A system according to any of embodiments 21-24 further
comprising componentry configured to return solids derived from the
slip stream back to a mash or saccharified liquor produced in the
facility.
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